1. Field of the Invention
The present general inventive concept relates to a judder detection apparatus, a de-interlacing apparatus using the judder detection apparatus, and a de-interlacing method, and more particularly, to a judder detection apparatus to detect whether an input image includes a blind pattern and to determine that a judder does not occur in the input image if the input image includes the blind pattern, and a de-interlacing apparatus using the judder detection apparatus, and a de-interlacing method.
2. Description of the Related Art
A blind pattern included in an output image indicates that every other line of an input image has a uniform pixel value and that pixel values of consecutive lines are different.
With the development of recent digital TV technology and large-scale screen display devices, such as plasma digital panel (PDP) TVs, projection TVs using digital lighting processing (DLP), liquid crystal displays (LCDs), and liquid crystal on silicon (LCoS), or the like, a high definition (HD) image can be enjoyed. As such, digital image devices have become popular, and an environment in which analog image devices such as TVs and digital image devices coexist, has been generalized.
Thus, existing analog TV images in the United States National Television Systems Committee (NTSC) screens or Standard Definition (SD) screens must be processed. In general, the existing analog TV images use interlaced scanning and may be applied to a HD screen by improving a resolution or a scanning rate. A conversion of the interlaced scanning image into de-interlaced scanning image is effective to improve the resolution or the scanning rate.
Image lines which do not exist in the interlaced scanning image are generated, converted into the de-interlaced scanning image, and displayed. This process is generally referred to as de-interlacing.
Here, the interlaced scanning and the de-interlaced scanning are classified according frame constitution methods. In the interlaced scanning, two fields are embodied and interposed line by line so as to constitute one frame. In other words, only odd lines of odd fields and even lines of even fields are scanned to embody the one frame using the two fields.
The de-interlaced scanning is also called a progressive method in which an image signal is scanned line by line to constitute one frame and a screen flickers less than in the interlaced scanning.
In the de-interlaced scanning, motion information or format transformation information of an image is used to switch a spatial interpolation for performing an interpolation using information within a field, and a temporal interpolation for performing an interpolation using information of consecutively input fields.
In general, an image in a film mode is generated through a combination of two consecutive fields, or a temporal interpolation is used in a still area. However, when the temporal interpolation is used according to wrong film information (i.e., an output image is generated through a combination of two sequentially input fields even though an input image is not in the film mode), or when two sequentially input fields are combined in a motion area of the input image to generate an output image, a judder occurs around the motion area.
Here, the judder is averagely displayed in a straight line on a screen. However, the judder indicates that a line of an image is microscopically displayed in a zigzag form. When judder is detected from the input image due to motion in the input image, it may be determined that the input image is in the film mode such that the consecutively input fields should be combined to generate the output image. In this case, a quality of the input image deteriorates. In other words, when the judder is detected from the input image, and the consecutively input fields are combined to generate the output image, the quality of the image may deteriorate.
Also, when the input image has a similar pattern to a judder pattern due to noise, a blind pattern, or the like, the input image is falsely detected as having the judder. Thus, the consecutively input fields are not combined to generate the output image. Moreover, even when the output image is generated using the temporal interpolation, the quality of the input image may deteriorate.